The long term objective of the proposed research is to find means to increase the rate of alcohol metabolism in humans for the treatment of acute intoxication and for the prevention of alcoholism. Since liver alcohol dehydrogenase catalyzes a rate limiting step in the removal of alcohol from the blood, we propose to synthesize active-site-directed compounds that will increase the activity of the enzyme in vivo. Modification of amino groups at the active sites of the horse liver enzyme increases the activity in vitro; the human enzyme can also be activated. The role of the amino groups in the mechanism of action of these enzymes will be defined by studies on the kinetics of enzymes that have the amino groups modified with varied substituents. Product inhibition, isotope exchange, and transient kinetics will be used. Various NAD ion and substrate analogs will be used, and the pH dependence of the kinetic parameters will be studied. Other amino acid residues participating in the activity of the enzyme will be identified by use of chemical modification and specific, active-site-directed reagents. Based on the topography of the active site, as determined from chemical modification, substrate and inhibitor binding, and x-ray crystallographic studies, active-site-directed reagents will be made that will specifically modify amino groups and activate the enzyme. Those that specifically activate the enzyme in vitro will be evaluated in vivo. If specific, activating reagents that are not too toxic and that can cross permeability barriers in animals are found, they would be valuable drugs for studying the metabolism and toxicology of ethanol and, perhaps, for therapy. Active-site-directed inactivators of alcohol dehydrogenase will be developed. These should also be useful in the treatment of alcoholics.